1. Field of the Invention
The present invention relates to an electric junction box in which an electronic circuit board and terminals are fixedly secured to a bed member, and the terminals are connected to bus bar terminals of a bus bar wiring board within the bed member.
The present application is based on Japanese Patent Application No. Hei. 10-225871, which is incorporated herein by reference.
2. Description of the Related Art
FIGS. 6 and 7 show the related electric junction box which has been disclosed in Unexamined Japanese Patent Publication No. Hei. 9-172720.
In this electric junction box 60, bus bar wiring boards 63 are provided in a stacked manner between an upper casing 61 (FIG. 7) and a lower casing 62, and an electronic circuit board 65 is mounted on one half portion of the bus bar wiring board 63 through a bed member 64, and the electronic circuit board 65 and the bus bar wiring boards 63 are connected together through relay terminals 66.
Support posts 67 for supporting the electronic circuit board 65 thereon are formed upright on the lower casing 62, and the bus bar wiring boards 63 are received between the opposed support posts 67. A plurality of tab terminals 69 are formed in an upstanding manner on bus bars 68 of the bus bar wiring board 63. A plurality of terminal portions 70, connected to a printed circuit (not shown), are formed at a peripheral portion of the electronic circuit board 65. One contact portion of each relay terminal 66 is connected to the associated terminal portion 70. Each group of relay terminals 66 are received in a housing 71, and in this condition each group of relay terminals 66 are connected to the terminal portions 70 laterally of the electronic circuit board 65. The housings 71 are provided at the opposite side edge portions of the electronic circuit board 65, respectively. The other contact portions of the relay terminals 66 are connected to the tab terminals 69 of the bus bars 68, respectively. The one contact portion of the relay terminal is disposed perpendicular to the other contact portion thereof.
Various parts, including diodes, noise filters, a buzzer for preventing a failure to turn off a light, and a buzzer for preventing a failure to withdraw a key, are mounted on the electronic circuit board 65. Second relay terminals 72, connected to the tab terminals 69 of the bus bars 68 are disposed in a fuse connection cavity 73 of the upper casing 61 (FIG. 7). A wire harness (not shown) is connected from the exterior to a connector portion 74 of the upper casing 61.
In the above construction, however, the connection between the bus bar wiring boards 63 and the electronic circuit board 65 requires many connecting portions, that is, the connection between the terminal portions 70 of the printed circuit and the one contact portions of the relay terminals 66 and the connection between the other contact portions of the relay terminals 66 and the tab terminals 69 of the bus bars 68. Therefore, there have been encountered problems that the number of the component parts is increased, so that the construction is complicated, that much time and labor are required for the connecting and assembling operations, and that the electrical contact resistance is increased. And besides, since the relay terminals 66 have a complicated construction, there has been encountered a problem that the costs of the component parts are high. There has been encountered a further problem that much time and labor are required for putting the relay terminals 66 into the housings 71. The housings 71 are provided respectively at two sides of the outer peripheral edge of the electronic circuit board 65 (in some cases, these housings are provided respectively at four sides of this outer peripheral edge), and therefore there has been encountered a further problem that the construction becomes complicated and bulky. The terminal portions 70 of the printed circuit must be provided at the outer peripheral edge portion of the electronic circuit board 65, and also the tab terminals 69 of the bus bars 68 must be provided in opposed relation to the outer peripheral edge of the electronic circuit board 65, and therefore there has been encountered a problem that the degree of freedom of the circuit arrangement, as well as the degree of freedom of arrangement of the connecting positions, is limited, so that the construction becomes complicated and bulky. The tab terminals 69 of the bus bars 68 can not be disposed at one half portion of the bus bar wiring board 63 beneath the bed member 64, and therefore there has been encountered a problem that a dead space is formed within the bed member 64, which also makes the electric junction box bulky. The upper surface of the upper casing 61 is stepped so that the electronic circuit board 65 can be disposed at a level higher than the bus bar wiring board 63, and this has invited a problem that the configuration is limited.